Combustion chamber thermic siphon



Jan. 7, 1941. G. J. CHRISTENSON COMBUSTION CHAMBER THERMIC SIPHON Filed Sept. 29, 1938 Patented Jan. 7, 1941 COMBUSTION CHAMBER THERMIC SIPHON Gust J. Christensen, Chicago, 111., assignor to Locomotive Firebox Company, Chicago, 11]., a corporation of Delaware Application September 29, 1938, Serial No. 232,348

6 Claims. (Cl. 122-68) This invention relates to improvements in combustion chamber thermic siphons and it con sists in the matters hereinafter described and more particularly pointed out in the appended claims.

In the use of a thermic siphon in the combustion chamber of a locomotive firebox, space limi tations are such that the conventional type of siphon does not function as efiiciently as desired. Heretofore the top end of the siphon opened through crown sheet portions of the chamber and the single inlet neck opened through the bottom sheet portion in line with the said top end. This made the siphon act as a rigid vertical strut in the combustion chamber which opposed relative movements between the sheet portions of the chamber.

In the heating up of the firebox, the crown sheet has a very definite upward movement and when the firebox cools down, the said sheet has an opposite or downward movement. Neither of these movements can be restrained. When such sheet movement occurs in a siphon equipped combustion chamber of the firebox, the siphon moves therewith by reason of its connection with the associated sheet portions of the chamber. Therefore, the stresses are localized in places not only in the siphon but in the sheet portions of the firebox combustion chamber. When these stresses exceed the elastic limit of said sheet portions in said chamber and in the siphon respectively, fractures occur.

One of the objects of the present invention is to provide an improved siphon which while capable of being used in the main fire chamber of a locomotive firebox, is especially. advantageous when used in the combustion chamber of the firebox, because it is more flexible and will accommodate relative sheet movement and thus prevent the localizing of stresses and therefore reduce fractures.

Another object of the invention is to provide a siphon for use in a combustion chamber which is capable of increasing the volume of water to flow through the siphon, thus not only giving a better water circulation but also increasing the steaming qualities of the boiler as a whole as well as better protecting the siphon against burning out.

Another object of the invention is to provide a combustion chamber siphon wherein it is possible to obtain longer and more flexible inlet necks therefor.

The above mentioned objects of the invention, as well as others, together with the advantages thereof will more fully appear as the specification proceeds.

In. the drawing:

Fig. l is a longitudinal vertical sectional view through the combustion chamber end of a locomotive boiler firebox, and associated boiler parts, illustrating the use of a siphon therein embodying one form of the invention.

Fig. 2 is a transverse vertical sectional view through the parts shown in Fig. 1 as taken on the line 2-2 of Fig. 1.

Fig. 3 is a view in perspective from one side, showing the improved siphon before trimming the top flange and the inlet necks to fit the installation to be made.

Fig.4 is a View in perspective from one end of the siphon appearing in Fig. 3.

Referring now in detail to that embodiment of the invention illustrated in the drawing: in indicates the crown sheet of a locomotive firebox which merges into the side sheets II, and I2 indicates the inner throat sheet of the firebox. The portion l3 of the crown sheet extends forwardly of the inner throat sheet to form the top of the combustion chamber M. This chamber is closed at the front end by a flue sheet l5 and the bottom sheet portion is of the combustion chamber merges into the front end of the inner throat sheet l2.

The boiler shell is. indicated at ll, the outer throat sheet is indicated at l8 and the mud ring, which is indicated at l9, provides the bottom for the front throat 20 which, of course, is in communication with the water space of the boiler. The structure described, which is conventional in a combustion chamber locomotive firebox, is staybolted in the usual manner.

In the combustion chamber 14 is located a ther- 4 mic siphon 2| that embodies one form of the in-- vention. Said siphon includes a somewhat elongated, flat hollow body 22 which is open at the top and has its opposite side walls staybolted as at 23. The body 22 has substantially upright bulged ends 24 and a bottom portion 25 between said ends, so that said body is open at the bottom of said ends. The entire top end of said body is provided with a laterally extending flange 26 which fits and is welded in an opening in the crown sheet portion l3 as indicated at 21.

The siphon has front and rear end inlet necks 28 and 29 respectively of a diameter corresponding to the width of the bulged ends 24-24, considered horizontally of the body and the top ends of said necks join the body at the respective open bottom end portions before referred to. The

upper portions of these necks extend downwardly and inwardly toward each other in the longitudinal plane of the body as best appears in Fig. 1. The remaining portions thereof extend further downwardly and then outwardly in opposite lateral directions, as appears in Fig. 2 to open through sheet portions of the combustion chamber toward the bottom thereof. The extremities of said remaining portions are engaged in suitable diaphragms 3E3. These diaphragms are preferably arranged in the same transverse line of the combustion chamber as is apparent Fig. 1. In Fig. 3 the inlet ends of said necks are shown as spaced apart longitudinally of the body for arranging in the desired positions according to the installation being made.

It is to be noted from Fig. 2 that no sharp corner portions are present in the inlet tubes, which, on the contrary, have a gradual upward and inward sweep into a portion of a curve of a generous radius that thereafter opens into the bottom end portions of the body. In this manner there are no pockets in said necks where sediment may accumulate. Turbulence cannot take place in said necks so that the water is free to flow as a solid column up through the inlet necks into the body.

In the relative movement of the top and bottom sheet portions of the combustion chamber, the inlet necks being relatively long and including a curved mid portion of generous radius, have sufilcient flexibility to accommodate the relative movement between said top and bottom sheet portions of the combustion chamber.

A thermic siphon of any suitable kind may be employed in the fire chamber and in Fig. 1 only a fragment of the front end of said siphon, bearing the numeral 3!, appears therein.

While in describing the invention, I have referred in detail to the form, arrangement and construction of the various parts thereof, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. In a locomotive boiler firebox having a brown sheet portion and other sheet portions,

a water steaming and circulating element in the firebox and including a flat hollow elongated body that opens at the top through said crown sheet portion, and a plurality of tubular inlet necks for said element formed as integral continuations of and extending downwardly from the ends of said body in opposite directions laterally of the longitudinal plane of the body and connected to certain of said other sheet portions of the firebox for receiving boiler water from points below said crown sheet portion.

2. In a locomotive boiler firebox having a crown sheet portion and other sheet portions, a hollow water steaming and circulating element longitudinally positioned in the firebox including a body that opens at the top through the crown sheet portion, and a plurality of tubular inlet necks for said element extending downwardly and inwardly toward each other from end portions of said body and in opposite directions laterally of the body and connected to certain of said other sheet portions of the firebox for receiving boiler water from points below said crown sheet portion.

3. In a locomotive boiler firebox having a crown sheet portion and other sheet portions, a water steaming and circulating element in the firebox including a fiat hollow elongated body that opens at the top through the crown sheet portion, said body having bulged ends of a diameter greater than the width of the body, and a plurality of tubular inlet necks, each of the same diameter as and joined at one end to an associated bulged end of the body and extending downwardly and outwardly from the longitudinal plane of the body in opposite lateral directions, the other end of said tubular inlet necks opening through certain of said other sheet portions for receiving boiler water from points below said crown sheet portion.

4. In a locomotive boiler firebox having a combustion chamber defined in part by a crown sheet portion and other sheet portions, a hollow water steaming and circulating element in said combustion chamber and including a body that is longitudinally positioned in the combustion chamber and opens at the top through said crown sheet portion, and a plurality of tubular inlet necks for said element each having an independent connection with and extending downwardly from an associated end of said body in opposite directions laterally of both the body and the combustion chamber and opening through certain of said other sheet portions thereof.

5. As an article of manufacture, a water steaming and circulating element for a locomotive boiler firebox including a flat hollow body open at the top and .closed at the ends and at a portion of the bottom, and tubular inlet necks for said body and each operatively connected to an associated end of the body as a continuation thereof and extending downwardly and inwardly toward each other and then downwardly and outwardly therefrom in opposite directions laterally of the body.

6. As an article of manufacture, a water steaming and circulating element for a locomotive boiler firebox including a fiat hollow body open at the top and having a closed bottom portion and closed bulged ends that extend downwardly and inwardly towards each other longitudinally of the body, and tubular inlet necks for said body of the same diameter as and forming continuations of said bulged ends and which extend downwardly and outwardly in opposite directions laterally of the longitudinal plane of the body.

GUST J. CI-IRISTENSON. 

